I've been having these spells, which I've been having a great deal of trouble describing. I didn't want to see a doctor about it until I was able to find comfortable terms of reference, and accurately describe what's going on. After much reading, the likeliest possibility seemed to be complex partial seizures. (I am however, no genius. Or doctor. And information I've found is all pretty clinical and generic, with little subjective description.)

So, the "spells" or "episodes"... It's like, all of a sudden, there's an intangible feeling of some kind of... not quite fear, but this all-consuming negative feeling. (Much like the feeling of dementors described in the Harry Potter books, if that makes sense.) An aura, perhaps? Then it feels like I no longer control my thoughts or brain-- I kinda zone out. It's like my current thoughts get "paused" and then someone else grabs the controller and takes over for a minute. Because then it's like thoughts/memories/dreams/hallucinations kinda flood in and float around in this mess I can't quite grasp. (Like that wet cornstarch slime stuff that you can sorta hold loosely, but if you actually try to grasp it, it slips away) I can't fully grasp it, but feel like I have some awareness of it while it's happening. It feels like really super-strong, powerful deja vu. Or almost like a waking dream bleeding into reality for a few seconds. But then once I move past the semi-hallucinating, I can no longer remember the content. I can remember that I recognized some of the content from a dream, or at least felt like it at the time-- but as for the actual substance of the thoughts/dreams, I never remember afterward. It's like the experience of "resting your eyes" (ie, napping) on the bus-- you feel awake and completely aware of what's going on around you, until you get jolted awake and realize that you were actually far less conscious than you thought and waaay past your stop!

That doesn't exactly describe the altered conciousness I experience with these "spells", but it's as close as my vocabulary comes to articulating something so non-tangible. But anyway, in addition to the weird dreamy stuff, there are also more readily identifiable physiological characteristics. After whatever happens in my head is over, I have a powerful hot flash (or at least what I imagine one feels like at 21, not being menopausal and thus lacking experience in hot flashes) --my whole body feels hot all over and only gradually dissipates into a duller, more subjective experience of generalised tension and negativity. Then there's rapid heartbeat, tingling, nausea, and sweating. (None of these symptoms necessarily in order-- these are just random observations made in the confusing wake of these spells.)

Does this description seem at all like it could be epilepsy? Or am I still in the dark on this one? (Perhaps someone's experienced something similar and looked into it only to get a different diagnosis-- I'd be happy to hear about alternate possibilities.)

It does sound like some type of seizure activity going on. You need to see a doctor and tell him just what you said in your post. He can do a EEG to see what is going on in your brain. There are meds you can take to control those before they get worst.